Recent versions of iCal can't seem to open Quorum's ICS files

According to the validator at http://icalvalid.cloudapp.net/Default.aspx , we're actually not producing valid ICS files. need to fix...

Relevant standards are in RFC 2445.

(from [a33a0323c9edc2f22fc49e85c58b77e062dd6312]) Fix date format. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/a33a0323c9edc2f22fc49e85c5...

(from [f0845b452a5ba3a7c93d07dc0a78b554c42c6a3e]) Add PRODID field to iCal export. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/f0845b452a5ba3a7c93d07dc0a...

(from [3e363105de91678381ffbb7cc25d9e0875b46539]) Escape location string. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/3e363105de91678381ffbb7cc2...

(from [690fcb0b7bd623047ce2032c05a1dfa1241f6a9a]) Use Windows-style line endings. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/690fcb0b7bd623047ce2032c05...

(from [f142048a7340eaa11315eb40517b49ffa51923b9]) Write spec for line ends. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/f142048a7340eaa11315eb4051...

(from [f3b7f138eaeede7230e5731a2ab90cdb5642ca78]) Add one more linefeed so iCal won't choke. [#65 Recent versions of iCal can't seem to open Quorum's ICS files] https://github.com/marnen/quorum2/commit/f3b7f138eaeede7230e5731a2a...